[Winderlust]

What is the proper grounding preparation against lightning for a new/used boat during commissioning/haul-out and also what is the proper lightning preparation for the boat and its gear heading into thunder storm conditions?

To add to the understanding, explain why such an approach. I saw somewhere in this "Sailnet Forum" from one cleaver captain that the Microwave, offshore, makes a good Faraday cage for handhelds: brilliant! Any other gems for the other pieces and say... the boat and crew?

 

[erps]

I think if you don't have a microwave, your oven might work too. I heard 2nd hand that one fellow clipped a quality set of jumper cables to his stays and let the other end trail in the water. I didn't hear that he experienced a strike to see if his theory worked though.

 

[MiVelero]

It would seem that if the MicroWave works why not the refrigerator/icebox ??

But in the end realize that anything you do in preparation for the situation the OP states, is nothing more than paliative care. Lighting will strike whenever if ever ....... no matter what you do. So for all practical purposes it is just a matter of chance. No?
I made out good because I had my electronics in the MW, and a jumper cable trailing behind me.... NO you was lucky and mother nature spared you.
Just a thought...

 

[Vasco]

When caught in an electrical storm I now resort to prayer. Having been hit once when 100 miles from my destination I've come to realize that there's nothing you can do. Note your position if within vhf distance to shore and pray. Put your handheld in the oven or on deck with you. As for bonding, not bonding, bottle washers on the masthead etc., etc., they don't do anything. My boat's through hulls were not bonded but when we hauled after the strike there was "treeing" (burn marks in the paint) at all the through hulls and at the gudgeon and pintle of the rudder. I think the good thing about my strike was that I have a wing keel (Hydrokeel) with a very large surface area which was good for dissipating the charge and the keel had a strap to the keel-stepped mast. As for jumper cables to the shrouds it might make you feel better but that's about all. There is a lot of literature on this subject and I read most of it after I was struck, that's why I pray now. Nothing else will do it!!

 

[erps]

Thanks for some first hand info Vasco. What other damage did you suffer?

 

[Vasco]

Headsail burnt, all masthead stuff vapourized, wiring shot, all instruments and lights shot, alternator shot, handheld in my foulies survived, no structural damage, no holes in hull. Biggest damage was to my psyche, never was scared of electrical storms before but now!!! Boat was hauled and inspected, mast removed. Took over six months to get everything right again. You know how some boatyard are. I chose the wrong one.

 

[sailingdog]

A better option for protecting small electronics is your pressure cooker. It forms a well-sealed faraday cage, thanks to the pressure gasket seal. A refrigerator, depending on what it is made of, may not be a good faraday cage. A microwave oven is probably less protective than a pressure cooker, since they're not solid metal all the way around.

 

[Noelex]

I always turn off my main battery switches. Any comments if this provides any slight protection for electronics, or am I wasting my time.

 

[Boasun]

Had a lightening strike on a boat I was working on.
It hit the SSB Antenna and blew out the coupler and the SSB before being grounded out into the steel hull of that boat. Needless to say that strike burned out all of the E. Boards in both the coupler and the SSB. And that antenna was nothing but splinters after the strike. Otherwise the steel hull & superstructure acted like a Faraday Cage and protected the crew.

 

[Noelex]

A better option for protecting small electronics is your pressure cooker. It forms a well-sealed faraday cage, thanks to the pressure gasket seal. .

Doesn't the gasket seal prevent electrical conductivity between the lid and base? This would make it a poor Faraday cage.

 

[Boasun]

Doesn't the gasket seal prevent electrical conductivity between the lid and base? This would make it a poor Faraday cage.

Odviously you haven't been around pressure cookers much. There is plenty of metal to metal contact between the lid and the pot. But you may want one big enough for you and your crew during heavy lightening strikes.

 

[Noelex]

Odviously you haven't been around pressure cookers much. There is plenty of metal to metal contact between the lid and the pot. But you may want one big enough for you and your crew during heavy lightening strikes.

I try to stay out of the galley, I guess it shows. My wife has just made a whole lot of orange marmalade in the pressure cooker I should have payed more attention.
I have an aluminium boat so I do have a Faraday cage big enough for me and my crew.

 

[Winderlust]

Let me Rephrase the Question

I should have been more specific with my question. I acknowledge that there is no way of preventing a lightning strike. My question addresses mitigation of danger and damage.

What I hear here is that all the bonding and grounding of house and boat is useless against lightning and that old Ben Franklin was a fraud as well as thousands after him.

Vasco your response has confused me. You say:

"As for bonding, not bonding, bottle washers on the masthead etc., etc., they don't do anything. My boat's through hulls were not bonded but when we hauled after the strike there was "treeing" (burn marks in the paint) at all the through hulls and at the gudgeon and pintle of the rudder."

Does this mean your boat was not properly bonded and grounded? If that was so how would anyone know how it would have reacted to the strike if it had been bonded and grounded to spec?

Am I to believe now when looking for my next boat I should ignore the quality of the boats bonding system and ground and instead pick up a prayer hymnal?

Also while under way in a thunderstorm, is there anything to avoid doing or touching and is there anything a good seaman should do besides pray?

Certainly an oven or heavy metal cookware makes sense for the backup GPSs and VHFs. Does a prudent seaman set the auto/vane and just go below?

 

[camaraderie]

Am I to believe now when looking for my next boat I should ignore the quality of the boats bonding system and ground and instead pick up a prayer hymnal?

Yes!

 

[Winderlust]

Saints Preserve Us

Well then Cam, know and good prayers or know were the good mojo is?

Cause sure as hell, if I'm out in it, I'm going to get hit, maybe twice.:hothead

 

[camaraderie]

Seriously...my attitude is that lightning is really bad news...especially if your mast is taller than most! I have had friends with top of the line boats, well bonded etc. get hit with both major damage and little damage. I don't think it matters.
I do what I can to avoid it and find that RADAR helps a lot in many situations to get around the squalls. I also take the sails in and turn the motor on to reduce the load on the rig AND make sure I don't ned to rely on my bateries or starter after I get hit! Ultimately...you just have to hunker down and hope you don't get hit and hope it isn't too bad if you do.
Electronics can be replaced but a mast coming down or a through hull being blown can be life threatening. Fortunately...if you are cruising you should be prepared for these things anyway and ready to implement emergency fixes since rigs and through hulls fail for other reasons as well.

 

[Winderlust]

Thanks

Now that's what I call an answer!!!

Use radar, check; Reduce rig load, check; Implement normal emergency tactics when called for, check.

Believe me, the question was quite serious; scares the sheet out of me.

Thanks for the serious answer Cam.

 

[sailingdog]

It won't help at all....if you get hit...the induced voltages won't care if the equipment is running or off... Most unhardened ICs require an an induced voltage of less than five volts to fry them in many cases...and with a lightning bolt's potential voltage and hundreds of thousands of amps...to drive it, that's relatively easy to achieve.

I always turn off my main battery switches. Any comments if this provides any slight protection for electronics, or am I wasting my time.

 

[Noelex]

It won't help at all....if you get hit...the induced voltages won't care if the equipment is running or off... Most unhardened ICs require an an induced voltage of less than five volts to fry them in many cases...and with a lightning bolt's potential voltage and hundreds of thousands of amps...to drive it, that's relatively easy to achieve.

Thanks Sailing dog I wont worry in future. I thought the large gap formed when the main battery switches are off may have been enough to encourage the high voltage to seek an alternative path rather than go via my expensive electronics at least with a nearby rather than direct hit. Hopefully Inside an aluminium boat the electronics receive a little protection from the induced voltage if a strike travels via the hull.
At least your advice saves me getting up in the night to turn off the battery switches.

 

[Vasco]

The charge went right through my boat from stem to stern. This could be seen by the "treeing" at all the through hulls. As for not touching anything we had to steer for another couple of hours (it was a big storm) as the autopilot was blown too. We did this by putting the wheel brake on and occasionally making corrections (very quickly) with a Rubbermaid glove on. I don't think the glove would have done anything but I felt better. We were afraid of touching anything metal. Cam is right, ignore the so-called "lightning proof" stuff they tell you when you buy a boat. A hymnal is not a bad idea.